The field of the present invention is devices that meter and dispense singular and plural component liquids and solids.
Systems for mixing and dispensing singular and multi-component materials are well known in the art. An almost infinite variety of substances may be dispensed. Many materials are packaged through dispensing in a fluid or a semi-fluid state. Paint is sprayed, molds are pressure charged with materials, and electronic devices are potted. A variety of means for distributing such materials are available. Where plural components are involved, such systems typically include pumping mechanisms for pumping and metering separate materials in a prescribed ratio to a mixing device that thoroughly mixes these materials together. The mixed composition then flows out of a dispensing nozzle directly to the surface or point of application where the composition is desired.
It has become quite advantageous to very carefully and accurately control the amount of material and sometimes the rate of flow of material dispensed. One such dispensing system is disclosed in U.S. patent application Ser. No. 08/752,768, filed Nov. 20, 1996, the disclosure of which is incorporated herein by reference. The system employs progressive cavity pumps and provides a system upon which the present disclosure is based. Additional details to the foregoing system are found in U.S. patent application Ser. No. 09/032,404, filed Feb. 27, 1998, the disclosure of which is incorporated herein by reference. These details provide features also applicable to the present disclosure. The employment of carefully controlled progressive cavity pumps in the foregoing disclosed systems provides for highly accurate dispensing of flowable materials.
The present invention is directed to dispensing systems employing one or more pumps and certain practical aspects enhancing accuracy and utility.
In a first separate aspect of the present invention, a dispensing system including at least one pump further includes a dispensing head. The dispensing head is arranged above the outlet of the pump. The outlet passage between the pump outlet and the dispensing head has a path which is continuously upward. Under circumstances where gas bubbles can migrate through the material to be pumped, the accumulation of gas is avoided, thereby increasing dispensing accuracy. Mixing accuracy is also enhanced where a plurality of pumps are employed with a dispense head.
In a second separate aspect of the present invention, a dispensing system includes one or more motors. The pump or pumps is/are driven by a motor or motors respectively. A bulkhead within the housing separates the pumps from the motors. Enhanced safety and system longevity are possible with such a system where flammable or corrosive materials are being handled.
In a third separate aspect of the present invention, the second aspect is further contemplated to include the bulkhead being a fireproof box open to outwardly of the housing. The fireproof box may further contemplate a cover, insulation and a heater or a liquid disposal capability through a drain.
In a fourth separate aspect of the present invention, a dispensing system includes one or more pumps feeding a dispensing head. The head includes one or more valves with a pneumatics actuator. The pneumatic actuator receives a controlled source of pressurized air through a solenoid valve. The dispensing head is mounted above the housing containing the pump or pumps and has the solenoid valve adjacent thereto. Increased accuracy is achieved through a reduction in control response time.
In a fifth separate aspect of the present invention, a dispensing system including a pump further includes a system for introducing fluid to the pump through distribution piping to both the inlet of the pump and the outlet of the pump. Air may also be introduced. A discharge from the inlet may also be contemplated as a convenient exhaust for residual pumped material and fluid. Such a system and the additions thereto are useful for the cleaning of material from the distribution system for system shutdown, decontamination or a change of distributed materials.
In a sixth separate aspect of the present invention, combinations of the foregoing aspects are contemplated.
Accordingly, it is an object of the present invention to provide a dispensing system with improved dispensing accuracy. Other and further objects and advantages will appear hereafter.